Inflatable hull structure and method of forming an inflatable boat hull

ABSTRACT

An inflatable boat includes a bottom structure made up of two or more inflated bottom tubes. Each bottom tube extends along the longitudinal axis of the boat from the stern end of the boat to the bow end of the boat. The bottom tubes are arranged side-by-side along at least a portion of their length, and when in an inflated condition, may directly provide a portion of the hull surface for the boat or at least support further components which provide portions of the hull surface. A front end of preferably each bottom tube is raised vertically relative to a back end of the respective bottom tube at the stern of the boat, and the relative size and/or position of the bottom tubes may be selected to define a desirable hull profile for the boat such as a V-shaped hull profile.

CROSS-REFERENCE TO RELATED APPLICATION

The Applicant claims the benefit, under 35 U.S.C. §119(e), of U.S.Provisional Patent Application No. 61/732,792 filed Dec. 3, 2012, andentitled “Inflatable Hull Structure and Method of Forming an InflatableBoat Hull.” The entire content of this provisional application isincorporated herein by this reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to inflatable boats, and, moreparticularly, to an inflatable boat having an inflatable hull structureproviding a desirable hydrodynamic shape. The invention also encompassesmethods for forming an inflatable boat hull.

BACKGROUND OF THE INVENTION

Inflatable boats find application in a wide variety of situations.Inflatable boats may be used as utility runabouts for large vessels, asfishing boats, and as military landing or boarding craft. Despite theirmany desirable characteristics, prior inflatable boats have certainnegative characteristics which reduce their usefulness. One undesirablecharacteristic of prior inflatable boats is that they provide arelatively unstable and low performance hull structure. In an effort toovercome this undesirable characteristic, some prior inflatable boatshave been fitted with rigid hull material. However, employing rigid hullmaterial has the disadvantage of negating some of the benefits ofinflatable boats, in particular, light weight and portability. Otherprior inflatable boat designs have employed an inflatable keel togetherwith a frame and fabric arrangement in an effort to produce a moredesirable hull shape for the craft. These designs tend to be complex andrelatively difficult to set up and break down.

SUMMARY OF THE INVENTION

The present invention provides an inflatable boat that may have adesirable hull shape without requiring any rigid frame or coverings. Inparticular, an inflatable boat according to the present invention mayuse inflatable tubes to produce a V-shaped hull or other desirable hullshape. In the following disclosure and claims relative positionalreferences such as front, rear, left, right, upper, lower, above, below,vertical, and horizontal refer to the orientation of the exampleembodiment shown in FIGS. 1 and 4 described below.

One embodiment of an inflatable boat according to the present inventionincludes a peripheral tube structure and two or more bottom tubes. Theperipheral tube structure includes a right side tube and a left sidetube which, in an inflated condition, define right and left sides of theboat respectively. These right and left side tubes of the peripheraltube structure may be referred to as the main buoyancy tubes of theinflatable boat. The right and left side tubes of the peripheral tubestructure each extend along a longitudinal axis of the boat from a sternend of the boat to a bow end of the boat, and meet at the bow end of theboat. Each bottom tube (which may also be referred to as a “floor tube”)also extends along the longitudinal axis from the stern end of the boatto the peripheral tube structure at the bow end of the boat. The bottomtubes are arranged side-by-side along at least a portion of theirlength, and when in an inflated condition, define a bottom tubestructure of the boat between the right side tube and left side tube.This bottom tube structure may directly provide a portion of the hullsurface for the boat or at least support further components whichprovide portions of the hull surface. A front end of preferably eachbottom tube is raised vertically relative to a back end of therespective bottom tube at the stern of the boat.

These and other advantages and features of the invention will beapparent from the following description of the preferred embodiments,considered along with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear view from an elevated perspective showing an inflatableboat according to one form of the present invention.

FIG. 2 is a rear view similar to FIG. 1, but showing a transom fitted tothe inflatable boat.

FIG. 3 is a rear right side view in perspective of the inflatable boatin FIG. 1, but with the ends of the inflatable tubes removed so as toshow the interior of each tube in the configuration it would reach in aninflated condition.

FIG. 4 is a right side view of the inflatable boat shown in FIG. 1

FIG. 5 is a perspective view in section taken along line 5-5 in FIG. 1.

FIG. 6 is a view similar to FIG. 5, but rotated so that the sectionalong line 5-5 in FIG. 1 is viewed from the side rather than inperspective.

FIG. 7 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to a second embodiment ofthe invention.

FIG. 8 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to a third embodiment ofthe invention.

FIG. 9 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to a fourth embodiment ofthe invention.

FIG. 10 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to a fifth embodiment ofthe invention, showing an alternate arrangement for forming the bottomtubes.

FIG. 11 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to a sixth embodiment ofthe invention, showing another alternate arrangement for forming thebottom tubes.

FIG. 12 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to a seventh embodiment ofthe invention, showing a further alternate arrangement for forming thebottom tubes.

FIG. 13 is a transverse section view through a stern end portion of thebottom tubes of an inflatable boat according to an eighth embodiment ofthe invention, showing a bottom material attached to the bottom tubes.

FIG. 14 is a transverse section view through a stern end portion of aninflatable boat according to a ninth embodiment of the invention,showing an arrangement in which the bottom tubes are encased in aflexible foam or other material.

FIGS. 15A-C each show a diagrammatic representation along a transverseplane of a respective bottom tube configuration employing drop stitchchambers.

FIGS. 16A-C each show a diagrammatic longitudinal profile of arespective bottom tube style which may be employed in embodiments of thepresent invention.

FIG. 17A is a front perspective view showing an assembly of bottom tubeshaving curved, tapered, and rotated bow portions.

FIG. 17B is a front view of the assembly of bottom tubes shown in FIG.17A.

FIG. 18A is a front perspective view showing an assembly of bottom tubeshaving constant-diameter curved bow portions.

FIG. 18B is a front view of the assembly of bottom tubes shown in FIG.18A.

FIG. 19 is a front perspective view showing an assembly of bottom tubesin a tunnel hull configuration.

FIG. 20 is a diagrammatic rear view of an inflatable boat according toan embodiment of the invention, with the transom removed to show a floorstructure connected to the bottom tubes to retain the bottom tubes in adesired configuration.

FIG. 21 is a side view of an inflatable boat according to anotherembodiment of the present invention.

FIG. 22 is a view in rear, left-side perspective of the inflatable boatof FIG. 21.

FIG. 23 is a front view in perspective from underneath the inflatableboat of FIG. 21.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring to the embodiment shown in FIGS. 1-6, an inflatable boat 100includes a peripheral tube structure 101 made up of a right side tube102 and a left side tube 104. The right side tube 102 and left side tube104 define right and left sides of the boat, respectively, and eachextend along a longitudinal axis L of the boat from a stern end of theboat shown generally at 106 to a bow end of the boat shown generally at108 (both ends labeled in FIGS. 1-4). The longitudinal axis L is shownin FIGS. 1 and 4, and, as indicated in FIG. 1, represents a centerlineof the boat. The right side tube 102 and left side tube 104 meet at thebow end 108 of boat 100.

Inflatable boat 100 also includes two or more bottom tubes 110 that alsoextend along longitudinal axis L from the stern end 106 to the bow end108 of the boat. When they are in an inflated condition the bottom tubes110 define a bottom support structure of the boat connected between theright side tube 102 and left side tube 104. In the embodiment shown inFIGS. 1-6, a front end of each bottom tube 110 is connected to theperipheral tube structure 101 at the bow end 108 of the boat. As shownbest in FIG. 6, each bottom tube has a front end that is raisedvertically relative to other portions of the respective tube. Thevertical offset is shown at dimension X between a lowermost level of thebottom tube and the lowermost surface of that bottom tube at its mostforward point. The example in FIG. 6 shows bottom tube 110 intersectingperipheral tube structure 101 within the dimension Y. Other embodimentsmay extend the bottom tubes 110 below (or even conceivably above) theperipheral tube structure at the bow of the boat. FIG. 6 also shows thatthe peripheral tube structure 101 is also elevated at the front of theboat such that the side tube 104 (and tube 102 although not shown inFIG. 6) has a front portion raised vertically with respect to the backportion at the stern end 106 of the boat.

FIG. 6 shows an example waterline W for inflatable boat 100. Thiswaterline W indicates the water level when the boat is resting in anoperating position on a body of water. It will be noted from FIG. 6 andfrom the side view of FIG. 4 that a portion of the bottom tubes 110extends below the side tubes 102 and 104. Thus portions of the bottomtubes 110 form the lowermost portion of the boat and boat hull.

The example of FIG. 5 shows that the bottom tube 110 through which thesection is taken has a diameter slightly more than one-half the diameterof the left side tube. However, bottom tubes 110 may be smaller orlarger than the side tubes 102 and 104. Some forms of the invention mayinclude no peripheral tube structure such as structure 101 and may formthe entire bottom of the boat from the side-by-side bottom tubes 110. Ofcourse in these embodiments including no peripheral tube structure, thebottom tubes provide the main buoyancy for the boat.

As shown in FIG. 2, inflatable boat 100 may be fitted with a transom 120which may receive an outboard motor (not shown). Transom 120 may besealed to the right and left side tubes 102 and 104, and also sealed tothe bottom tubes 110. In the form of the invention shown in FIG. 2,transom 120 is sealed to the ends of the bottom tubes 110 at the sternend 106 of boat 100.

FIGS. 1, 2, and 4 also show that the right and left side tubes 102 and104 may each include a rearwardly tapered end portion 122.

The inflatable tubes employed in any of the embodiments of the presentinvention (such as tubes 102, 104, and 110 shown in FIGS. 1-6) may beformed from a tube chamber made of a flexible material and one or moreair-tight bladders made of a suitable flexible material. The one or morebladders may be inserted into the respective chamber material andinflated to reach an inflated condition for that tube. Bladders may alsobe inflated first at least partially and then inserted into therespective tube chamber.

Alternatively, the tube chamber material itself may form an air-tightchamber made of a suitable material such as a rubber-coated orelastomer-coated fabric which may be inflated to reach an inflatedcondition for that tube.

The bottom tubes for a given embodiment (such as bottom tubes 110 inFIGS. 1-6) may be isolated and inflated separately, or may be connectedso that all of the bottom tubes 110 may be inflated simultaneously.

Although the tubes 102, 104, and 110 are shown as single structures inthe embodiment of FIGS. 1-6, each may be divided into separate chamberswhich are separately sealed and inflated. The portions of the right andleft side tubes 102 and 104 at the bow end 108 of the boat in particularmay be formed from several different chambers in order to help producethe desired upward offset.

One or more of the bottom tubes for a given embodiment may include or beentirely made of one or more drop stitch chambers having a suitabletransverse shape, such as oblong for example, as shown in FIGS. 15A-C.The peripheral tube structure (including left and right side tubes 104and 102 in the embodiment of FIG. 1) may also include drop stitchchambers.

The material forming the tube chambers may be connected in any mannersuitable for the type of material, such as sonic welding, heat welding,adhesive material, sewing, or any combinations of these, for example.

Where connections are required between the various tubes (such as tubes110, 102, and 104 in the embodiment of FIGS. 1-6), the connections maybe made in any suitable fashion. FIGS. 7, 10, 11, and 12 illustrateseveral different arrangements for connecting the bottom tubes togetherin embodiments of the present invention. FIG. 7 shows bottom tubes 710connected together with material strips 711. These connecting materialstrips 711 may be connected to the bottom tubes 710 via an adhesive, bya welding technique, or any other technique suitable to the connectingmaterial and the tube material. The alternative embodiment of FIG. 10shows that the various bottom tubes 1010 may be connected together withthe same material forming the tube chambers for those tubes. Theembodiments of FIGS. 11 and 12 show bottom tubes 1110 and 1210,respectively, which are also interconnected via the material which formsthe tube chambers in those embodiments.

FIGS. 13, 14, and 20 each show a different arrangement for connecting orpositioning the bottom tubes of the respective embodiment. In theexample of FIG. 13, bottom tubes 1310 are retained together in thedesired side-by-side position by a top material 1301 spanning the fourbottom tubes, and by a foam material structure 1324 which includes aflexible or rigid bottom layer 1325. The example of FIG. 14 shows thebottom tubes 1410 completely incased in a foam material structure 1424.This foam material structure 1424 may be made in upper and lower halves(not shown in the figure), which may be placed together so as to trapthe bottom tubes 1410 in the desired location relative to one another. Alayer of upper cover material 1425 is shown extending between side tubes1402 and 1404 to form the floor surface of the boat in this embodiment,while a bottom layer of material 1426 forms the exterior of the hull.FIG. 20 shows that a separate top member 2001 may be used to connect thebottom tubes 2010 together to provide the desired bottom structurebetween left and right side tubes 2004 and 2002, respectively. Topmember 2001 may also provide a floor of the boat.

It will be appreciated from the embodiment of the invention shown inFIGS. 1-6, and from the embodiments of FIGS. 17A and 18A, that thebottom tubes of an inflatable boat according to the present inventionneed not be of the same length.

The present invention encompasses many variations regarding the bottomsupport structure formed from the bottom tubes. As shown particularly inFIGS. 7, 8, and 19, the number and size of the bottom tubes 710, 810,and 1910, respectively, connected together to produce the bottom supportstructure may be varied to approximate different hull shapes. Theembodiment of FIG. 7 employs four bottom tubes 710 while the embodimentof FIG. 8 employs five bottom tubes 810. The embodiment of FIG. 19includes nine bottom tubes 1910. Various hull shapes which may beapproximated by various bottom tube configurations will be describedfurther below.

The foam or other lightweight flexible material 1324 and 1424 shown inthe embodiments of FIGS. 13 and 14, respectively, not only provides anarrangement for positioning the respective bottom tubes in thoseembodiments, but also provides a desired hull shape. In the case of FIG.14, the material 1424 also provides a desired floor shape for the boat.FIGS. 16A-C show three different alternatives for the longitudinal shapeof each bottom tube in an inflatable boat according to the presentinvention. FIG. 16A shows a bottom tube 1610A having a longitudinallycurved front section. A number of bottom tubes 1610A may be usedtogether according to the invention to provide an upwardly curvedforward hull for the resulting boat. FIG. 16B shows a bottom tube 1610Bhaving a front portion that is angled upwardly along a single linerelative to the remainder of the bottom tube. FIG. 1610C shows anembodiment of a bottom tube 1610C having a front portion made up ofmultiple parts which together approximate an upward curve.

FIGS. 17A-B and 18A-B show two different arrangements of bottom tubes1710 and 1810, respectively, arranged to form a respective bottomsupport structure for an inflatable boat according to the presentinvention. The arrangement of FIGS. 17A-B includes five separate bottomtubes 1710. Each bottom tube 1710 includes a rear section 1701 and afront section 1702, with each front section being curved upwardly andtapering in diameter toward the front of the structure. Because thebottom tubes 1710 taper smaller in diameter toward the front of thebottom structure, the outer two bottom tubes 1710 are angled inwardly.The angle for the outermost bottom tube 1710 is shown at R in FIG. 17B.The arrangement of FIGS. 18A-B also includes five separate bottom tubes1810. Each bottom tube 1810 includes a rear section 1801 and a frontsection 1802 that is curved upwardly toward the front of the bottomstructure but maintains a constant diameter. The upwardly curved orextending portions of the bottom tubes toward the front of the boat helpgenerate lift at the bow of the boat as it is operated under power.

Although FIGS. 17A-B show that the bottom tubes 1710 all taper smallerin diameter toward the bow end of the boat, other arrangements mayinclude some bottom tubes which increase in size toward the bow end ofthe boat, while other bottom tubes decrease in size. Furthermore, one ormore of the bottom tubes may have a shape that includes a bulge. Forexample, the boat 2100 shown in FIGS. 21-23 includes a center bottomtube 2110 that includes a bulge at B to help fill the area between theadjacent bottom tubes where they curve upwardly. All of the bottom tubes2110 are arranged between side tubes 2102 and 2104 similarly to theembodiment shown in FIGS. 1-6. The embodiment shown in FIGS. 21-23 alsoincludes a transom 2120 mounted at the stern end of bottom tubes 2110.

As shown in FIG. 11, contact between two adjacent bottom tubes 1110 inthe arrangement of bottom tubes may cause the bottom tube material toform essentially an I-beam shape which can contribute to thelongitudinal stiffness of the boat. The I-beam shapes may or may not bereinforced with extra layers of material. Extra layers of material ordifferent types of material in these regions may enhance stiffness ofthe resulting structure. In the example of FIG. 11, the I-beam shapebetween adjacent bottom tubes 1110 comprises pieces of material 1111separate from an outer cover material 1112.

In some preferred forms of an inflatable boat hull according to thepresent invention, the bottom tubes, when in the inflated condition, lieside-by-side with essentially no gaps there between along the entireside-by-side length. Connecting material or an additional layer ofmaterial particularly along the bottom sides of the bottom tubes may beused to eliminate gaps between adjacent tubes. The bottom tubearrangement shown in FIG. 14 is an example where a bottom material 1424fills the gaps between adjacent bottom tubes 1410.

One of the advantages of the present invention is that the arrangementof bottom tubes (bottom tubes 110 in FIGS. 1-6, for example) may form acomplete hull for the boat. This complete hull may or may not beintegral to the remainder of the boat. Also, the arrangement of bottomtubes may form an upper support surface which provides the floor or deckfor the boat, or provides a support surface for one or more floor/deckmembers.

Another advantage of the present invention is that the side-by-sidearrangement of elongated bottom tubes (bottom tubes 110 in FIGS. 1-6,for example) forms or approximates a desired hull profile (the profilebeing the shape along a line perpendicular to the longitudinal axis L ofthe boat). FIG. 7 shows a bottom structure made up of four bottom tubes710 including two inner bottom tubes and two outer bottom tubes. Thesmaller diameter of the outer bottom tubes 710 and their positionrelative to the inner two bottom tubes 710 help approximate a V-shapedbottom shown by dashed line 701 and define a horizontal upper planeshown by dashed line 702. FIG. 8 shows an arrangement of five bottomtubes including a center bottom tube 810, two progressively smallerdiameter bottom tubes 810 on either side of the center bottom tube. Thisarrangement of five bottom tubes 810 in FIG. 8 also approximates aV-shaped hull profile indicated by dashed line 801, and defines ahorizontal top plane 802. FIG. 9 shows another way in which bottom tubesmay be used to approximate a “V” hull profile. In the case of FIG. 9,all of the bottom tubes 910 have the same diameter, and a rigidstructure or cross member 930 (or series of cross members spaced apartalong the length of the bottom structure) connects across the top of twooutside bottom tubes 910 (not necessarily the outermost bottom tubes) toforce the bottom tubes 910 into the desired hull configuration. Thesetwo techniques, using different diameter bottom tubes 910, and using arigid structure or cross member 930, may also be combined to produce abottom tube arrangement having the desired hull profile. Additionally,as is particularly apparent from FIGS. 15A-C, the angular position atwhich adjacent bottom tubes are connected together may be used toinfluence the profile of the resulting hull. Although FIGS. 15A-C usedrop stitch type, oblong bottom tubes 1510A, 1510B, and 1510C,respectively, the angular position connection technique may be used withcircular bottom tubes or with other bottom tube transverse shapes. Forexample, the angular position of each outer bottom tube 710 shown inFIG. 7 with respect to the adjacent inner bottom tube 710 helps definethe desired “V” shape 701. Also, angular connection position, bottomtube relative size, and a rigid top structure or cross member (such ascross member 930 in FIG. 9 for example) may be combined to produce thedesired hull profile. Of course, the bottom tube relative size technique(illustrated in FIGS. 7 and 8 for example) may be used to create adesired hull profile using just the side-by-side bottom tubes withoutany rigid members needed to support the hull structure.

Although all of the illustrations show bottom tube arrangementsincluding bottom tubes of a single transverse shape (for example, allcircular in FIG. 8 and all oblong in FIG. 15A), forms of the inventionmay mix bottom tube shapes. For example, a center bottom tube may have acircular transverse shape (like center tube 810 in FIG. 8), and theouter bottom tubes may be oblong shaped (like tubes 1510A in FIG. 15A),or any other suitable shape or combination of shapes.

In a desirable hull configuration such as a “V” hull profile shown inFIG. 8 for example, the center bottom tube 810 provides the lowermostbottom surface of the boat. This tube providing the lowermost bottomsurface may be referred to as a bilge tube since it makes up thelowermost chamber of the boat. The bottom of the adjacent bottom tubes810 are raised vertically (direction Z in FIG. 8) with respect to thebottom surface of the bilge/center bottom tube 810. It will beappreciated that some desired hull shapes may include two spaced apartbilge tubes. FIG. 19 provides an example of such a hull structureproduced by bottom tubes 1910 to form a double V-shaped hull profile.

As used herein, whether in the above description or the followingclaims, the terms “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” and the like are to be understood to beopen-ended, that is, to mean including but not limited to. Any use ofordinal terms such as “first,” “second,” “third,” etc., in the claims tomodify a claim element does not by itself connote any priority,precedence, or order of one claim element over another, or the temporalorder in which acts of a method are performed. Rather, unlessspecifically stated otherwise, such ordinal terms are used merely aslabels to distinguish one claim element having a certain name fromanother element having a same name (but for use of the ordinal term).

The above described preferred embodiments are intended to illustrate theprinciples of the invention, but not to limit the scope of theinvention. Various other embodiments and modifications to thesepreferred embodiments may be made by those skilled in the art withoutdeparting from the scope of the present invention.

1. An inflatable boat including: (a) a peripheral tube structureincluding a right side tube and a left side tube which, in an inflatedcondition, define right and left sides of the boat, respectively, andeach extend along a longitudinal axis of the boat from a stern end ofthe boat to a bow end of the boat, and meet at the bow end of the boat;and (b) two or more bottom tubes which, in an inflated condition, definea bottom support structure of the boat extending laterally across thespace between the right side tube and left side tube, each bottom tubeextending along the direction of the longitudinal axis of the boat witha front end of each bottom tube raised vertically relative to a back endof the respective tube at the stern end of the boat, the bottom tubesresiding side-by-side along at least a portion of their length to formthe bottom support structure.
 2. The inflatable boat of claim 1 whereinthe peripheral tube structure is offset vertically in the bow end of theboat relative to the portion of the peripheral tube structure at thestern end of the boat.
 3. The inflatable boat of claim 1 including threeor more bottom tubes.
 4. The inflatable boat of claim 1 wherein at leastone of the bottom tubes intersects the peripheral tube structure at thebow end of the boat.
 5. The inflatable boat of claim 1 wherein thebottom tubes are connected together by flexible connecting material toform the bottom tube structure.
 6. The inflatable boat of claim 1further including a floor member to which each bottom tube is connectedto retain each bottom tube in a desired configuration relative to eachother bottom tube.
 7. The inflatable boat of claim 1 further including abottom forming material positioned to receive one or more of the bottomtubes and provide a bottom surface for the inflatable boat.
 8. Theinflatable boat of claim 7 further including a top forming materialpositioned to receive one or more of the bottom tubes and provide afloor surface within the inflatable boat.
 9. The inflatable boat ofclaim 1 further including a floor structure mounted above the bottomtubes.
 10. The inflatable boat of claim 1 wherein one or more of thebottom tubes is tapered in the bow end of the boat to a smaller crosssectional dimension in the direction from the stern end of the boat tothe bow end of the boat.
 11. The inflatable boat of claim 10 whereineach tapered bottom tube has a tapered portion that curves upwardlytoward the bow end of the boat.
 12. The inflatable boat of claim 1wherein each pair of adjacent bottom tubes define a respective uprightI-beam segment of bottom tube material there between.
 13. The inflatableboat of claim 1 wherein one or more of the bottom tubes comprises abilge tube providing a lowermost bottom surface of the boat along aportion of its respective length and a bottom tube adjacent to one ofthe bilge tubes provides a lower surface which is raised vertically withrespect to a lower surface of that bilge tube at least along a portionof the length of that bilge tube.
 14. A method of forming an inflatableboat hull for a boat including a peripheral tube structure having aright side tube and a left side tube which, in an inflated condition,define right and left sides of the boat respectively and each extendalong a longitudinal axis of the boat from a stern end of the boat to abow end of the boat, and meet at the bow end of the boat, the methodincluding: (a) arranging two or more bottom tubes side-by-side to form abottom tube assembly extending laterally in the area between the rightside tube and the left side tube; (b) connecting a front end of eachbottom tube to the peripheral tube structure at the bow end of the boatwith each bottom tube also extending rearwardly along the longitudinalaxis of the boat to the stern end of the boat; (c) connecting the bottomtube assembly at a right side thereof to the right side tube andconnecting the bottom tube assembly at a left side thereof to the leftside tube; and (d) inflating each bottom tube to an inflated conditionin which at least two or more of the bottom tubes include a frontportion which is raised vertically with respect to a back portion of therespective bottom tube at the stern end of the boat.
 15. The method ofclaim 14 wherein the bottom tube assembly includes one or moreinflatable bladders contained in at least one of the bottom tubes andinflating each such bottom tube includes inflating the one or moreinflatable bladders.
 16. A boat including: (a) two or more adjacentbottom tubes which, in an inflated condition, form a bottom structuremaking up at least a portion of a lowermost part of a hull of the boat,the lowermost part of the hull comprising a part located below awaterline for the boat when the boat is resting in an operating positionon a body of water; and (b) each bottom tube extending in the directionof a longitudinal axis of the boat and having a respective front endthat is raised vertically with respect to at least a portion of thatbottom tube.
 17. The boat of claim 16 wherein the two or more adjacentbottom tubes include: (a) one or more center bottom tubes having a firsttransverse dimension; and (b) one or more outer bottom tubes outside ofone of the one or more center bottom tubes, the one or more outer bottomtubes having a second transverse dimension smaller than the firsttransverse dimension of the one or more center bottom tubes.
 18. Theboat of claim 16 wherein the bottom structure includes a sufficientnumber of adjacent bottom tubes to extend laterally across the width ofthe boat to form an integral deck for the boat or an integral decksupport surface.
 19. The boat of claim 16 further including: (a) aninflatable right side peripheral tube extending in the direction of thelongitudinal axis along a right side of the bottom support structure todefine a right side of the boat; and (b) an inflatable left sideperipheral tube extending in the direction of the longitudinal axisalong a left side of the bottom support structure to define a left sideof the boat, the right and left side peripheral tubes extending inwardlytoward a centerline of the boat and meeting at a bow end of the boat,and the right and left side peripheral tubes defining a peripheral tubestructure for the boat.
 20. The boat of claim 19 wherein the bottomtubes intersect the peripheral tube structure at the bow end of theboat.